1. Field of the Invention
The present invention relates generally to a gooseneck for use in coiled tubing operations. More specifically, the invention describes a pivoting gooseneck incorporating a linkage mechanism that allows for safer, more stable operation.
2. Description of the Prior Art
Coiled tubing operations typically involve at least three primary components. The coiled tubing itself is disposed on a reel and must, therefore, be dispensed onto and off of the reel during an operation. The tubing extends from the reel to an injector. The injector moves the tubing into and out of the wellbore. Between the injector and the reel is a tubing guide or gooseneck. The gooseneck is typically attached or affixed to the injector and guides and supports the coiled tubing from the reel into the injector. Typically, the tubing guide is attached to the injector at the point where the tubing enters. As the tubing wraps and unwraps on the reel, it moves from one side of the reel to the other (side to side). The gooseneck typically has a flared end that accommodates this side to side movement.
In performing a coiled tubing job or operation, the components required for the job (i.e., at least the coiled tubing reel, gooseneck and injector) are transported separately to the wellsite, thereby adding the expense of additional personnel and equipment (e.g., additional trucks). Once on site, the gooseneck must be attached to the injector. This increases set-up time and expense.
One of the drawbacks of the basic gooseneck is that the flared end restricts the side to side movement or motion that can be tolerated by the system. There is an existing modification of the basic gooseneck (known as a “pivoting gooseneck”) that swivels or rotates about the centerline of the injector to allow greater side to side movement of the coiled tubing. For ease of description, the gooseneck position wherein its sides are parallel to the sides of the reel (i.e., wherein the coiled tubing is substantially centered on the reel), will be called the mean position or the zero degree position. However, the major drawback of the pivoting gooseneck is that it has a maximum potential energy at the mean position (i.e., a point on the gooseneck structure traces a path of an inverted “U” or inverted parabola as the gooseneck moves from side to side). This puts the pivoting gooseneck in unstable equilibrium. This unstable equilibrium has the tendency to push the gooseneck to either side. In certain situations, this tendency may cause the gooseneck to fall off the ends or may cause uneven or irregular motion of the tubing and/or gooseneck.